Yellowjackets and paper wasps are

benefi cial insects. They feed their

young numerous insects that ordinarily

damage shade trees and crops. They

also kill countless fl ies and various other

pest insect species.

While yellowjackets and paper wasps are often confused, they have some distinct differences. Yellowjackets are relatively short and stout compared to paper wasps. Paper wasps have longer, more slender bodies and dangling legs. Yellowjacket nests are spherical and are enclosed in a papery envelope with a small entrance hole. Paper wasp nests are usually suspended from eaves or porch ceiling and look like tiny umbrellas fi lled with hexagonal cells.

Life Cycle

SACRAMENTO–YOLO MOSQUITO AND VECTOR CONTROL DISTRICT

YELLOWJACKETS AND PAPER WASPS

OFFICE LOCATIONS AND HOURS OF OPERATION

Sacramento County8631 Bond RoadElk Grove, CA 95624Phone: 1-800-429-1022Fax: 916-685-5464Web site: FIGHTtheBITE.net Hours: 7:00 am to 3:30 pm

Yolo County1234 Fortna AvenueWoodland, CA 95695Phone: 1-800-429-1022Fax: 530-668-3403Web site: FIGHTtheBITE.netHours: 7:00 am to 3:30 pm

adult

egg

pupa

larva

YELLOWJACKETSYellowjackets are social insects that live in a nest containing workers, queens and males. Two species are common in the Sacramento region, Vespula pensylvanica and Vespula germanica.

AppearanceYellowjackets are medium sized black wasps with yellow markings and black or yellow antennae. Workers are usually about a ! inch long and appear short and stocky while the queen is larger at about " of an inch. Workers are often confused with honey bees, but in contrast, are not covered with dense hair on their bodies.

NestDepending on the type of yellowjacket, they build aerial or subterranean nests. Nests are built of wood fi bers and consist of multiple stacked combs completely enclosed by a paper envelope, except for a small entrance. Nests of most species are placed underground in rodent burrows or other soil cavities.

BehaviorMost of the time, yellowjackets are not aggressive and will not harm you if you stay out of their way. However, when a nest is disturbed, yellowjackets will swarm and can infl ict multiple stings that are painful and may be life threatening to individuals hypersensitive to the venom.

PAPER WASPSPaper wasps are social insects that live in colonies containing an alpha female, workers, and males. The European Paper Wasp, Polistes dominulus, is common to the Sacramento region.

AppearanceThe European Paper Wasp is often mistaken for a yellowjacket because of its yellow and black coloration. One distinct difference is the orange-tipped antennae. Like other paper wasps, it is narrow-waisted, and during fl ight, its legs trail below in an extended fashion.

NestPaper wasps build nests of wood fi ber and consist of a single comb not enclosed by an envelope. Nests of the European paper wasp are often less than 100 cells in size but may be constructed of over 400 cells. This wasp appears to be quite fl exible in selecting nesting sites, including roof eaves, within meter boxes, bird houses, outdoor grills, benches and within shrubbery.

BehaviorEuropean paper wasps are more easily provoked than other wasps, and will more readily sting when someone nears their nest. An unsuspecting homeowner may be stung, for instance, when attempting to change an outdoor light bulb, opening a gate, or while gardening. European paper wasps, like other wasps, can sting repeatedly.

ENTRANCE

COMBSNESTSUPPORT

ENVELOPE

NEST ENTRY

YELLOWJACKET CONTROL In the summer months, foraging yellowjackets may become a nuisance in parks, campgrounds and other areas. Yellowjackets can be managed through:

Sanitation· Tightly cover garbage receptacles and move from eating

areas to reduce food available to foraging workers· Eliminate standing water to help reduce the water

available for cooling the nest and drinking

Depletion TrappingWhile this method can help to reduce foraging workers, it is not an effective method for eliminating yellowjackets. Commercially available traps use a chemical lure to attract foraging workers into a container with a one way passage. Once inside, the insect cannot escape and dies. Traps should be placed in areas away from food and people.

PAPER WASP CONTROLPaper wasps may become a nuisance when they build a nest on or near your home. Every attempt should be made to limit suitable nest sites:· Repair holes in walls· Caulk cracks in eaves· Screen vents and louvers

NEST CONTROL FOR YELLOWJACKETS& PAPER WASPSNests may require control when their location becomes a problem. While there are products available on the market, there is always a risk of personal injury involved when treating yellowjacket nests. Call a private pest control company or your local vector control agency for recommendations. (Please note: Depletion trapping, as used for yellowjackets, does not attract paper wasps and will not reduce their numbers.)

FIRST AID FOR STINGSFor any sting:· Wash with soap and cold waterFor allergic reactions:· Seek immediate medical careFor multiple stings or hypersensitive persons:· Seek immediate medical care· Do not wait for symptoms to develop